Baby stroller folding mechanism

ABSTRACT

This invention involves a set of exclusive methods of folding mechanisms for means of collapsing and opening a baby stroller. The methods aims for the compact ability, ease of use, versatility and easy manufacturing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser. No. 61/662,930, filed on Jun. 22, 2012.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates methods of folding mechanism on a baby stroller to conveniently collapse a baby stroller and more particularly, is directed to baby strollers which fold with single hand operation.

2. Discussion of Related Art

In recent years, several inventions have been developed in attempt to produce an easy method of collapsing the stroller. One particular prior art worth mentioning is a collapsible baby stroller by Sutherland et al. (U.S. Pat. No. 6,102,431) involving a folding, mechanism that uses a two knife blade followers to engage the spring loaded piston in an unfolded position. With this present invention, followers are not necessary, thus, reduces extra parts to be made. This will reduce the manufacturing cost and time. Mechanism such as stoppers—gear locking slots, protrusion tab—latch and plug—hole positioned in strategic places described in first, second and third embodiments provides a strong locking system to maximize the rigidity of the entire frame structure.

In the fourth, fifth and sixth embodiments, the gears are placed in face-to-face juxtaposition. In comparison with the collapsible baby stroller by Chili-Ching Cheng (U.S. Pat. No. 7,632,035B2), the embodiments of this present invention providing a solution for better fixation of the pinion gears on folding mechanism by eliminating the need of using rotatable members with apertures. Therefore, this reduces not only manufacturing cost and time; it also allows increases the durability of the gear component as one solid component instead of having apertures on its surface. In addition, two of the embodiments of the present invention eliminates the need of installing the spring locking system on rear wheel support bar.

SUMMARY OF THE INVENTION

The present of this invention is series of methods of folding baby stroller, which improve the ease of folding a baby stroller and lessen the bulkiness of the stroller for storage. Embodiments of the folding mechanism involve two gears moving simultaneously in the opposite direction to guide the movement of folding mechanism. The two gears are further connected to the two main parts of the stroller—the front wheel(s) and the handle bar(s), by means of extensions. One gear is connected to the extension to front wheel(s), the other is connected the extension to the handle bar. The embodiments further include a locking mechanism to halt the movement of the two gears indefinitely until the locking mechanism is disengaged. The locking mechanism, in a few embodiments is further connected to the extension of the rear wheels. In other embodiments, the locking system is an independent mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an exemplary implementation of baby stroller embodying the present invention shown in unfolded state.

FIG. 2 is an isometric view of the stroller frame of FIG. 1.

FIG. 3 is a side elevation view of the stroller frame of FIG. 2.

FIG. 4 is a side elevation view of the stroller frame with a folding mechanism shown in fully folded state.

FIG. 5 is an enlarged fragmentary view of the folding mechanism according to an embodiment of present invention with its outer housing removed and in fully unfolded state.

FIG. 6 is exploded view corresponding to FIG. 5 of the folding mechanism.

FIG. 7 is an enlarged fragmentary view of the folding mechanism according to the second embodiment of present invention with its outer housing removed and in fully unfolded state.

FIG. 8 is exploded view corresponding to FIG. 7 of the folding mechanism.

FIG. 9 is an enlarged fragmentary view of the folding mechanism according to the third embodiment of present invention with its outer housing removed and in fully unfolded state.

FIG. 10 is exploded view corresponding to FIG. 9 of the folding mechanism.

FIG. 11 is an enlarged fragmentary view of the folding mechanism according to the fourth embodiment of present invention with its outer housing removed and in fully unfolded state.

FIG. 12 is exploded view corresponding to FIG. 11 of the folding mechanism.

FIG. 13 is an enlarged fragmentary view of the folding mechanism according to the fifth embodiment of present invention with its outer housing removed and in fully unfolded state.

FIG. 14 is exploded view corresponding to FIG. 13 of the folding mechanism.

FIG. 15 is an enlarged fragmentary view of the folding mechanism according to the sixth embodiment of present invention with its outer housing removed and in fully unfolded state.

FIG. 16 is exploded view corresponding to FIG. 15 of the folding mechanism.

FIG. 17 is an enlarged fragmentary view of the folding mechanism according to the seventh embodiment of present invention in fully unfolded state.

FIG. 18 is exploded view corresponding to FIG. 17 of the folding mechanism.

FIG. 19 is side view, corresponding to FIG. 17 of the folding mechanism.

DETAILED DESCRIPTION OF INVENTION

The stroller frame is made up of three sections; front wheel support 2, push handle support 4, rear wheel support 3 (See FIG. 2). The left and right front wheels are mounted to the end of the front wheel supports 2. The stroller push handle 5 is mounted to the left and right of the push handle support 4 and the left and right of rear wheels are mounted to end of the rear wheel supports 3. These sections are hinged by a folding mechanism 6 (See FIG. 1) placed on both side of the stroller. The stroller, in the unfolded position depicted in FIG. 3, has the from wheel support 2 and push handle support 4 aligned in a straight line. Conversely, the stroller, in the folded position, is depicted in FIG. 4.

The folding mechanism 6 consists of two outer casing 10 a, 10 b, two gear components 15, 16 and a locking system 80 (See FIG. 5 and FIG. 6). The gear components each consists of a mesh gear with a bar that extends to become the front wheel support 4 or the push handle support 2. The gear components can be made as an entire piece to include all its parts or be made separately. Both gear components 15, 16 are mounted on pivots of the folding mechanism 6. The gears constrain the movement between the front wheel support 2 and push handle support 4, so either one is rotates toward the rear wheel support, the other one will rotate toward rear wheel support as well. The mesh gear is partially toothed or can be of any type of gear as long as it achieves the same result as above. At the end of the sequence of gear teeth is a gear locking slot 17. The gear locking slot 17 is slightly different from the tooth spaces as its main function is to provide a fit for the stopper 14 from the locking system 80.

The locking system 80 consists of a spring loaded piston 12, connected to a central bar 13 with stoppers 14 at the ends of the bar. The stoppers 14, can be made of lug, bar, tab; are positioned with means to constrain the movements of both gear components 15, 16 by insertions into the gear locking slot 17 of each gear component 15, 16. The locking system 80 can also be designed with spring loaded piston connects to only one stopper engaging on one gear locking slot 17 on either side of the gear component instead of both sides since locking one gear component will prevent another gear component to move.

When folding, the stoppers 14 on the locking system 80 are retracted from the gear locking slots 17, thereby freeing both gear components 15, 16 to rotate with the influence of force gravity pulling and hence the collapsing of the front wheel support 2 and push handle support 4. In the case, depicted in FIG. 2 the push handle 5 of stroller that is connected to the left and right push handle supports 4 at one end rotates anti-clockwise, while the front wheels that are connected to the left and right front wheel supports 2 at the other end rotates clockwise. Thus, the final result is a folded stroller depicted in FIG. 4.

The stroller, in the unfolded position depicted in FIG. 3, has the front wheel support 2 and push handle support 4 aligned in a straight line. During the unfolding process, each gear component 15, 16 moves upwardly, with sequence of teeth on the mesh gear rotates in the opposite direction, until the stoppers 14 falls into the gear locking slot 17 with the release of the loaded tension in the locking system 80 (See FIG. 5). The rotation of the gear components is further constrained by lack of gear teeth on the other end of the teeth sequence. The remaining tension from in the locking system 80 maintains the stoppers 14 in contact with the gear locking slots 17 prevent the front wheel support 2 and push handle support 4 from folding.

The retraction of locking system 80 can be achieved by lifting up the pull bar or lever 19. The lever 19 is connected to the locking system via pin 18 (See FIG. 6). The position of the lever can be extended away from the locking system 80 to be in closer proximity to the stroller user by using means such as cable wires on locking system 80 and levers 19 to control the locking operation. The stroller will fold only when both levers 19 on each side of the stroller, are lifted up simultaneously. This can be achieved by connecting both levers 19 on each side of the stroller with a handle strap.

Instead of using the stoppers 14 and gear locking slots 17 for means of initiating and halting the movement of the gear components 15, 16, in the folding mechanism 6 a, a modification can be made to one of the gear components where a protrusion tab 21 is positioned at the end of the sequence of gear teeth of the gear component 26 (See FIG. 7 and FIG. 8). The protrusion tab 21 acts as stopper for a complimentary latch 22, which is connected to the locking system 81. The locking system 81 consists of a spring loaded piston 12, connected to a latch 22.

When folding, latch 22 retracted away from the protrusion tab 21, allowing the movement of the gear components 25, 26. The bar of the gear components will move downwardly with influence of gravity force. When unfolding, the gear components 25, 26, rotate in the opposition direction with the gear teeth surface sliding along the surface of latch 22 as tension from the loaded spring keeps a light contact between the gear teeth and the surface. When the protrusion tab 21 passes the tip 22 a of latch 22, the tension from the spring loaded piston 12 will cause latch 22 to anchor onto the protrusion tab 21, thereby halting the movement of the gear components 25, 26. The latch 22 and protrusion tab 21 can be of any size and shape as long as it able to engage to each other.

In another embodiment, instead of having gear locking slots 17 or protrusions 21, a locking hole 37 on the surface of one of the gear components of the folding mechanism 6 b and a spring loaded plug 34 is being used (See FIG. 9 and FIG. 10). A lever 29 is attached to the spring loaded plug 34 by cable wire 11 to control the movement of the plug.

When the front wheel support 2 and push handle support 4 are in the process of unfolding, the plug 34 of the locking mechanism slides along the surface of the gear component 35 until it finally meets with hole 37 and engages with the hole 37 due to the tension release of spring, thereby locking the rotator movement of the gear components 35, 36. To fold, the lever 29 is lifted up to retract the spring of the plug 34, thereby removing the plug 34 from the hole 37. Both gear components 35, 36 begin to rotate freely with the influence of gravity force on the front wheel support 2 and push handle support 4 to fold the stroller. One of the benefits of this embodiment is that the locking system is no longer attached to the rear wheel support 3. In this design, the locking system can be placed on lateral side or any position of the folding mechanism 6 b instead on rear wheel support 3.

The fourth embodiment is a folding mechanism 6 c consisting of two outer casing 20 a, 20 b, two gear components 45, 46; two pinion gears 41, 42; and a locking, system 82 (See FIG. 11 and FIG. 12). The two gear components 45, 46 are placed in face-to-face juxtaposition. Each gear component has a set of gear teeth in a partial hollow cut from the surface. In FIG. 12, the series of gear teeth is along the bottom lip of the hollow cut 45 a (radially inward gear) of the first gear component 45, while a second series of gear teeth is along the top lip of the hollow cut 46 a (radially outward gear) of second gear component 46. The hollow cut 45 a, 46 a can be part of the gear component itself (by stamping or molding) or can part of made as individual piece attached to each of the bar connected to front wheel support 2 and push handle bar 4.

The pinion gears 41, 42 are positioned in the hollow cut on gear components 45, 46 for driving engagement of folding mechanism 6 c. The gear teeth of first pinion gear 41 is positioned to engage on the gear teeth of the first gear component 45 while the gear teeth of second pinion gear 42 is positioned to engage with the gear teeth of the second gear component 46. Both pinion gears are coupled to rotate simultaneously about a common axis fixed by the pin 43 connected to an arm 40. The arm 40 is further connected to the bolt 47 at the center of the gear components to secure the common axis in place. Hence if one of the gear components is rotated, the rotational force is transferred to the pinion gears to cause the other gear component to rotate. For example, when the push handle support 4 is rotated towards to the rear wheel support 3, the front wheel support 2 is rotated simultaneously towards the rear wheel support 3 as well. The two pinion gears can be manufactured as a single unit or by two separate units attached as one entity. Each gear component 45, 46 further consist of a near locking slot 49 a, 49 b on the edge to engage with a stopper 48 connected to the locking system 82. The locking system 82 consists of a spring loaded piston 12 which is attached to the end of outer casing 20 a, 29 b. The end of the outer casing further connected to a rear support wheel 3. A lever 19 is connected to the locking system 82 via pin 18 for retracting the stopper 48.

To fold the stroller, the lever 19 is lifted up to retract the stopper 48. The stopper 48 detaches from the gear locking slots 49 a, 49 b and frees the two gear components 45, 46 to rotate. Since the gear components 45, 46 are further attached to front wheel support 2 and push handle support 4 respectively, the weight of both ends, due to gravity, will cause the stroller to fold slowly. The position of the lever 19 can be extended away from the locking system 82 to be in closer proximity to the stroller user by using means such as cable wires on locking system 82 and levers 19 to control the locking operation.

It is worth mentioning that as an alternative embodiment of the locking mechanism 82, a receptor block 52 is connected the locking system 83 to engage with the protrusion tabs 51 a, 51 b at the gear component (See FIG. 14). The receptor block 52 has a hollow section or it can be a hole or a slot to engage with the protrusion tabs 51 a, 51 b of gear components. The folding mechanism 6 d is able to operate in a similar fashion. This is depicted in FIG. 13 and FIG. 14.

To fold the stroller, the lever 19 is lifted up to retract the spring loaded receptor block 52. The receptor block 52 detaches from the protrusion tabs 51 a, 51 b and frees the two gear components 55, 56 to rotate. Since the gear components 55, 56 are further attached to the front wheel support 2 and push handle support 4 respectively, the weight of both ends, due to gravity, will cause the stroller to fold slowly.

When unfolding, the gear components 55, 56, rotate in the opposition direction with the edge of both gear components sliding along the surface of receptor block 52 as tension from the loaded spring keeps a light contact between the gear components and the receptor block 52. When the protrusion tabs 51 a, 51 b reach the tip of the receptor block 52, the tension released will cause the receptor block 52 to rise, thereby fitting the protrusion tabs 51 a, 51 b into the hollow slot 52 a, halting the movement of the gear components 55, 56. The receptor block 52 and protrusion tabs 51 a, 51 b can be of any size and shape as long as they able to engage to each other.

In another embodiment of the folding mechanism 6 e, is a hole 67 on the of the gear surface of one or both of the gear components 65, 66. This is depicted in FIG. 15 and FIG. 16. The hole 67 is positioned on the surface of a gear component 65 adjacent to the outer casing 61 a of the folding mechanism compartment 6 e. A plug 64 is attached to the outer casing 61 a. The movement of the plug 64 is guided by tension created with either cable tension or spring loaded. The purpose of the plug 64 is to initiate and stop the movement of the gear component 65 since locking one gear component will prevent another gear component to move. To initiate the process of folding, as tension is applied from the cable, the plug 64 is being pulled away from the hole 67 of the gear component 65, allowing initiation of movements of the gear components. With the guidance of the pinion gears 41, 42, all rotatable gears move in accordance as stated in previous embodiment until the push handle support 4 and front wheel support 2 are parallel with each other. When the front wheel support 2 and push handle support 4 are in the process to be unfolded, the gear components 65, 66 to move in accordance with the pinion gears 41, 42 in the folding mechanism in the opposite direction. The tensioned plug 64 slides along the surface of the gear component 65 until it drops into the hole 67 of the gear component 65 to halt the movement of the gears, thereby, keeps the stroller in fully unfolded position. The locking mechanism can also be achieved with a hole position on gear component 66 with tensioned plug engaging on gear component 66 to prevent another gear component to move.

In another embodiment, the folding mechanism 6 f now consist of two gear components 75, 76, a bevel gear controller 71, housing 90 a, 90 b and a locking system 70 (See FIG. 17 and FIG. 18). The locking system 70 consists of blocker support 74 and spring loaded piston 12 positioned inside the spring support holder 74 a (See FIG. 18). The spring support holder 74 a further connects to rear wheel supports 3 (not shown). The two gear components 75, 76 are placed in face-to-face juxtaposition. The bolt 91 inserted to gear hub 92 to clamp the housing 90 b of the folding mechanism secure the two gear components 75, 76. The gear controller 71 can be of a bevel gear or any shape gear as long as it achieves the same result. The gear components 75 further contains a stopping pin 72 fixed on its disk surface while another gear component 76 consists of a stopping groove 73. As usual, the gear component 75 is connected to the front wheel support 2 and the gear component 76 is connected to the push handle support 4 of the stroller. The gear controller 71 initiates the simultaneous movement of the two gear components 75, 76, by rotating on a vertical axis. The gear controller 71 initiates the gliding of the stopping pin 72 along the stopping groove 73, as both gear components rotates simultaneously, in FIG. 19, the gear controller 71 further consists of a locking slit 77 (female connector) on its edge. The blocker support 74 has a protruded blocker 78 act as a male connector to lock the female connector of gear controller 71 when the spring is released. The locking slit 77 has right-angled shaped 77 a on one end and a slope 77 b on other end. The protruded blocker 78 has right-angled shaped apex 78 a on one end and a slope 78 b on other end. The gear controller 71 is rotatable but the blocker support 74 is non-rotatable and only move vertically alone with the spring.

When folding the stroller, the lever 19 is engaged to retract blocker support 74, thereby removing protruded blocker 78 from the locking slit 77, allowing the gear controller 71 to rotate. The stopping pin 72 guides the gear controller 71 to rotate one direction until stopping pin 72 reaches the end of the stopping groove 73. Since the gear components 75, 76 are further attached to front wheel support 2 and push handle support 4 respectively, the weight of both ends, due to gravity, will cause the stroller to fold slowly. The stopping pin 72 glides in the direction from one end of the stopping groove 73 to the other end.

At the end of folded position, the protruded blocker 78 rest on the surface of the gear controller 71 with tension from the loaded spring holding it in place.

When unfolding the stroller, the initial upward pulling of the push handle 4 which is connected to gear component 76 will starts the rotation of the gear controller 71 in a clockwise direction (from the top view). The rotation in the clockwise direction will continue with the locking slit 77 slide out of the slope 78 b of the protruded blocker 78 effortlessly, until the stopping pin 72 glides from one end of the groove 73 to the other. At the end of the unfolding process, the stopping pin 72 will prevent the gear components from further unfolding. The locking slit 77 will rest in the protruded blocker 78 with angled shaped apex 78 a of protruded blocker 78 engage with the right-angled shaped 77 a of the locking slit 77, thereby prevent the folding movement (anti-clockwise direction) of the gear components 75, 76. The combination of groove 73, stopping pin 72, protruded blocker 78 and locking slit 77 result in an locking system on gear components 75, 76. The locking slit 77 and protruded blocker 78 can be of any size shape as long as it able to engage to each other. 

1. A folding mechanism for stroller comprising: (a) a pair of gear components wherein each gear component comprises at least one gear having plurality of teeth, and said each gear component having an axis of rotation laterally spaced from the other respective axis of rotation; first gear component connects with as bar further extends to become the front wheel support of the stroller; second gear component connects with a bar further extends to become the push handle support of the stroller; and (b) a locking system comprises at least one spring loaded piston means for constraining the movement of said gear components.
 2. The folding mechanism according to claim 1, wherein the locking system further connect to the rear wheel support of the stroller.
 3. The folding mechanism according to the claim 1, wherein said gear component comprises at least one gear locking slot, and at least one of said gear locking slot further engages with at least one stopper, and said stopper being connected to the locking system.
 4. The folding mechanism according to the claim 1, wherein said gear component comprises at least one protrusion tab, and at least one of said protrusion tab further engages with at least one latch, and said latch being connected to the locking system.
 5. The folding mechanism according to claim 1, wherein said gear component further comprises of at least one hole on the surface, and at least one of said hole further engages with the at least one plug, and said plug being connected to locking system.
 6. A folding mechanism for stroller comprising: (a) a pair of gear components, wherein gear components being coupled to rotate about common axis of rotation; each near component comprises of gear in partial hollow cut from the surface; first gear component having plurality of gear teeth along the bottom lip of the hollow cut and second gear component having plurality of gear teeth along the top lip of the hollow cut; one gear component connects with a bar further extends to become the front wheel support of the stroller and the other gear component connects with a bar further extends to become the push handle support of the stroller; (b) at least one pinion gear, wherein said pinion gear having plurality of gear teeth is positioned in the hollow cut of the surface of said gear component; said pinion gear further engage on gear teeth of gear components so that said gear components rotate relative to each other; (c) at least one arm, wherein at least one of said arm connects to a bolt at the center of said gear component and means for coupling at least one of said pinion gear; and (d) a locking system comprising of at least one spring loaded piston means for constraining the movement of said gear component.
 7. The folding mechanism in claim 6, wherein the locking system further connects to the rear wheel support of the stroller.
 8. The folding mechanism in claim 6, wherein each gear component further comprises of at least one gear locking slot, and at least one of said gear locking slot further engages with the at least one stopper, and said stopper being connected to the locking system.
 9. The folding mechanism in claim 6, wherein each gear component further comprises of at least one protrusion tab, and at least one of said protrusion tab further engages with at least one receptor, and said receptor being connected to the locking system.
 10. The folding mechanism in claim 6, wherein each gear component further comprises of at least one hole on the surface, and at least one of said hole further engages with the at least one plug, and said plug being connected to locking system.
 11. A folding mechanism for stroller comprising: (a) a pair of gear components, wherein each gear component comprises at least one gear having plurality of teeth; and said gear components being coupled to rotate about common axis of rotation; first gear component connects with a bar further extends to become the front wheel support of the stroller; second gear component connects with a bar further extends to become the push handle support of the stroller; (b) at least one gear controller, wherein said gear controller having plurality of teeth means for constraining the movement of said gear components; and (c) a locking system, wherein said locking system means for constraining the movement of said gear controller.
 12. The folding, mechanism according to claim 11, wherein said locking system further comprises at least one blocking support means for engaging said gear controller.
 13. The folding mechanism according to claim 11, wherein said locking system further comprises at least one spring loaded piston positioned inside the spring support holder and said spring support holder being connected to rear wheel support of the stroller.
 14. The folding mechanism according to claim 11, wherein one gear component further comprises at least one stopping pin and the other gear component further comprises at least one stopping groove.
 15. The folding mechanism according to claim 11, wherein said gear controller is a bevel gear.
 16. The folding mechanism according, to claim 12, wherein at least one of said gear controller further comprises of at least one locking slit.
 17. The folding mechanism according to claim 16, wherein art least one of said locking slit has right-angled shaped on one end and a slope on other end.
 18. The folding mechanism according to claim 16, wherein at least one of said blocking support further comprising at least one protruded blocker, and at least one of said protruded blocker further engages the at least one locking slit of said gear controller when spring is release.
 19. The folding mechanism according to claim 18, wherein said protruded blacker has right-angled shaped apex on one end and a slope on other end. 